We plan to study the natural history of herpesvirus infections in three human populations known to have persistent infection with these agents. We plan to study sites of excretion of virus, clinical consequences of infection, and host response to virus in renal transplant recipients, women with cervical cytomegalovirus (CMV) excretion,, and children with congenital CMV. Infection with herpesviruses is widespread among renal transplant patients; they also have a high rate of malignancy. In this population we will determine frequency of infection with all four herpesviruses (Epstein-Barr virus, CMV, Herpes simplex virus (HSV), and Varicella-zoster (VZ)). We will examine factors in the clinical setting of transplantation, such as immunosuppression and histocompatibility, that may affect viral latency, leading to active infection or possibly malignant transformation of infected cells. Young women with cervical CMV excretion will be characterized by site of excretion of virus and frequency of recurrences, in relation to age, parity, and transmission of virus to a fetus or newborn. Through long-term follow-up, changes in cervical cytology, including development of malignancy, will be correlated with viral epidemiologic data. In congenitally CMV infected children, ongoing follow-up will be used to determine rates of malignancy in this population compared to uninfected controls.